@article{lang_strynar_lindstrom_farthing_huang_schmid_hill_chernoff_2020, title={Toxicity of Balb-c mice exposed to recently identified 1,1,2,2-tetrafluoro-2-[1,1,1,2,3,3-hexafluoro-3-(1,1,2,2-tetrafluoroethoxy)propan-2-yl]oxyethane-1-sulfonic acid (PFESA-BP2)}, volume={441}, ISSN={["0300-483X"]}, DOI={10.1016/j.tox.2020.152529}, abstractNote={1,1,2,2-tetrafluoro-2-[1,1,1,2,3,3-hexafluoro-3-(1,1,2,2-tetrafluoroethoxy)propan-2-yl]oxyethane-1-sulfonic acid (PFESA-BP2) was first detected in 2012 in the Cape Fear River downstream of an industrial manufacturing facility. It was later detected in the finished drinking water of municipalities using the Cape Fear River for their water supply. No toxicology data exist for this contaminant despite known human exposure. To address this data gap, mice were dosed with PFESA-BP2 at 0, 0.04, 0.4, 3, and 6 mg/kg-day for 7 days by oral gavage. As an investigative study, the final dose groups evolved from an original dose of 3 mg/kg which produced liver enlargement and elevated liver enzymes. The dose range was extended to explore a no effect level. PFESA-BP2 was detected in the sera and liver of all treated mice. Treatment with PFESA-BP2 significantly increased the size of the liver for all mice at 3 and 6 mg/kg-day. At the 6 mg/kg-day dose, the liver more than doubled in size compared to the control group. Male mice treated with 3 and 6 mg/kg-day and females treated with 6 mg/kg-day demonstrated significantly elevated serum markers of liver injury including alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), and liver/body weight percent. The percent of PFESA-BP2 in serum relative to the amount administered was similar in male and female mice, ranged from 9 to 13 %, and was not related to dose. The percent accumulation in the liver of the mice varied by sex (higher in males), ranged from 30 to 65 %, and correlated positively with increasing dose level.}, journal={TOXICOLOGY}, author={Lang, Johnsie R. and Strynar, Mark J. and Lindstrom, Andrew B. and Farthing, Amy and Huang, Hwa and Schmid, Judith and Hill, Donna and Chernoff, Neil}, year={2020}, month={Aug} }
 @article{lang_allred_field_levis_barlaz_2017, title={National Estimate of Per- and Polyfluoroalkyl Substance (PFAS) Release to U.S. Municipal Landfill Leachate}, volume={51}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/acs.est.6b05005}, DOI={10.1021/acs.est.6b05005}, abstractNote={Landfills are the final stage in the life cycle of many products containing per- and polyfluoroalkyl substances (PFASs) and their presence has been reported in landfill leachate. The concentrations of 70 PFASs in 95 samples of leachate were measured in a survey of U.S. landfills of varying climates and waste ages. National release of PFASs was estimated by coupling measured concentrations for the 19 PFASs where more than 50% of samples had quantifiable concentrations, with climate-specific estimates of annual leachate volumes. For 2013, the total volume of leachate generated in the U.S. was estimated to be 61.1 million m3, with 79% of this volume coming from landfills in wet climates (>75 cm/yr precipitation) that contain 47% of U.S. solid waste. The mass of measured PFASs from U.S. landfill leachate to wastewater treatment plants was estimated to be between 563 and 638 kg for 2013. In the majority of landfill leachate samples, 5:3 fluorotelomer carboxylic acid (FTCA) was dominant and variations in concentrations with waste age affected total estimated mass. There were six PFASs that demonstrated significantly higher concentrations in leachate from younger waste compared to older waste and six PFAS demonstrated significant variation with climate.}, number={4}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Lang, Johnsie R. and Allred, B. McKay and Field, Jennifer A. and Levis, James W. and Barlaz, Morton A.}, year={2017}, month={Feb}, pages={2197–2205} }
 @article{lang_allred_peaslee_field_barlaz_2016, title={Release of Per- and Polyfluoroalkyl Substances (PFASs) from Carpet and Clothing in Model Anaerobic Landfill Reactors}, volume={50}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.5b06237}, abstractNote={Discarded carpet and clothing are potential sources of per- and polyfluoroalkyl substances (PFASs) in landfill leachate, but little is known about their release when disposed in landfills. The concentrations of 70 PFASs in the aqueous phase of anaerobic model landfill reactors filled with carpet or clothing were monitored under biologically active and abiotic conditions. For carpet, total PFAS release was greater in live than abiotic reactors, with an average of 8.5 nmol/L and 0.62 nmol/L after 552 days, respectively. Release in live carpet reactors was primarily due to 5:3 fluorotelomer carboxylic acid (FTCA - 3.9 nmol/L) and perfluorohexanoic carboxylic acid (PFHxA - 2.9 nmol/L). For clothing, release was more dependent on sample heterogeneity than the presence of biological activity, with 0.63, 21.7, 2.6, and 6.3 nmol/L for two live and two abiotic reactors after 519 days, respectively. Release in the clothing reactors was largely due to perfluorooctatonic carboxylic acid (PFOA), with low relative concentrations of measured biotransformation precursors (FTCAs). For carpet and clothing reactors, the majority of PFAS release was not measured until after day 100. Results demonstrate that carpet and clothing are likely sources of PFASs in landfill leachate.}, number={10}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Lang, Johnsie R. and Allred, B. McKay and Peaslee, Graham F. and Field, Jennifer A. and Barlaz, Morton A.}, year={2016}, month={May}, pages={5024–5032} }
 @article{allred_lang_barlaz_field_2015, title={Physical and Biological Release of Poly- and Perfluoroalkyl Substances (PFASs) from Municipal Solid Waste in Anaerobic Model Landfill Reactors}, volume={49}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.5b01040}, abstractNote={A wide variety of consumer products that are treated with poly- and perfluoroalkyl substances (PFASs) and related formulations are disposed of in landfills. Landfill leachate has significant concentrations of PFASs and acts as secondary point sources to surface water. This study models how PFASs enter leachate using four laboratory-scale anaerobic bioreactors filled with municipal solid waste (MSW) and operated over 273 days. Duplicate reactors were monitored under live and abiotic conditions to evaluate influences attributable to biological activity. The biologically active reactors simulated the methanogenic conditions that develop in all landfills, producing ∼140 mL CH4/dry g refuse. The average total PFAS leaching measured in live reactors (16.7 nmol/kg dry refuse) was greater than the average for abiotic reactors (2.83 nmol/kg dry refuse), indicating biological processes were primarily responsible for leaching. The low-level leaching in the abiotic reactors was primarily due to PFCAs ≤C8 (2.48 nmol/kg dry refuse). Concentrations of known biodegradation intermediates, including methylperfluorobutane sulfonamide acetic acid and the n:2 and n:3 fluorotelomer carboxylates, increased steadily after the onset of methanogenesis, with the 5:3 fluorotelomer carboxylate becoming the single most concentrated PFAS observed in live reactors (9.53 nmol/kg dry refuse).}, number={13}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Allred, B. McKay and Lang, Johnsie R. and Barlaz, Morton A. and Field, Jennifer A.}, year={2015}, month={Jul}, pages={7648–7656} }
 @article{allred_lang_barlaz_field_2014, title={Orthogonal zirconium diol/C18 liquid chromatography-tandem mass spectrometry analysis of poly and perfluoroalkyl substances in landfill leachate}, volume={1359}, ISSN={["1873-3778"]}, DOI={10.1016/j.chroma.2014.07.056}, abstractNote={Leachates coming from landfills contain a myriad of compounds of potential environmental and human health concern, including per- and polyfluorinated alkyl substances (PFASs). Micro liquid-liquid extraction was combined with a 900 μl large volume injection (LVI) for the analysis of 70 PFASs in landfill leachate by orthogonal LC-MS/MS. The LVI approach introduced 7 times more extract than conventional injection approaches. Two zirconium-modified diol guard columns effectively retained PFASs from the organic leachate extract and an analytical C18 column was used for separation. Method accuracy and precision for PFASs with analytical grade reference materials ranged from 81–120% and 5.5–33%, respectively. Estimated method detection limits in the low to sub-ng/L. Seven landfill leachates were analyzed by the optimized analytical method for the purposes of method demonstration. Leachates were characterized by a wide variety of PFASs, reporting on 36 previously-unanalyzed PFASs in leachate. Perfluoroalkyl carboxylates were the most abundant class detected while phosphorous-containing PFASs, present in all leachates, were at low concentrations. The 3-perfluoropentyl propanoate (5:3 FTCA) was the most concentrated analyte in most samples and constitutes a previously unreported but significant component of landfill leachate.}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Allred, B. McKay and Lang, Johnsie R. and Barlaz, Morton A. and Field, Jennifer A.}, year={2014}, month={Sep}, pages={202–211} }